ALBERT

Description: With the growing population, solid waste management (SWM) is becoming a significant environmental challenge and an emerging issue, especially in the eco-sensitive Indian Himalayan region (IHR). Though IHR does not host high local inhabitants, growing tourist footfall in the IHR increases solid wastes significantly. The lack of appropriate SWM facilities has posed a serious threat to the mountain-dwelling communities. SWM is challenging in the highlands due to the remoteness, topographical configuration, increasing urbanization, and harsh climate compared to plain areas. Difficulty in managing SWM has led to improper disposal methods, like open dumping and open burning of waste, that are adversely affecting the fragile IHR ecosystem. Open dumping of unsegregated waste pollutes the freshwater streams, and burning releases major pollutants often linked to the glacier melt. Processes like composting, vermicomposting, and anaerobic digestion to treat biodegradable wastes are inefficient due to the regions' extreme cold conditions. IHR specific SWM rules were revised in 2016 to deal with the rising problem of SWM, providing detailed criteria for setting up solid waste treatment facilities and promoting waste-to-energy (WtE). Despite governments' effort to revise SWM; measures like proper collection, segregation, treatment, and solid waste disposal needs more attention in the IHR. Door-to-door collection, segregation at source, covered transportation, proper treatment, and disposal are the primary steps to resource recovery across the IHR. Approaches such as waste recycling, composting, anaerobic digestion, refuse-derived fuel (RDF), and gas recovery from landfills are essential for waste alteration into valuable products initiatives like 'ban on single-use plastic' and 'polluters to pay' have a potential role in proper SWM in the IHR. Research and technology, capacity building, mass awareness programs, and initiatives like ‘ban on single-use plastic’ and ‘polluters to pay’ have a potential role in proper SWM in the IHR. This review highlights the current status of waste generation, the current SWM practices, and SWM challenges in the IHR. The review also discusses the possible resource recovery from waste in the IHR, corrective measures introduced by the government specific to IHR and, the way forward for improved SWM for achieving sustainable development of the IHR.

Description: Background Night-soil compost (NSC) has traditionally been conserving water and a source of organic manure in northwestern Himalaya. Lately, this traditional method is declining due to modernization, its unhygienic conditions, and social apprehensions. Reduction in the age-old traditional practice has led to excessive chemical fertilizers and water shortage in the eco-sensitive region. In the current study, a bacterium has been analyzed for its safety, cold-adaptation, efficient degradation, and plant growth-promoting (PGP) attributes for its possible application as a safe bioinoculant in psychrotrophic bacterial consortia for improved night-soil composting. Results Glutamicibacter arilaitensis LJH19, a psychrotrophic bacterium, was isolated from the NSC of Lahaul valley in northwestern Himalaya. The strain exhibited amylase (186.76 ± 19.28 U/mg), cellulase (21.85 ± 0.7 U/mg), and xylanase (11.31 ± 0.51 U/mg) activities at 10 °C. Possessing efficient hydrolytic activities at low-temperature garners the capability of efficient composting to LJH19. Additionally, the strain possessed multiple PGP traits such as indole acetic acid production (166.11 ± 5.7 μg/ml), siderophore production (85.72 ± 1.06% psu), and phosphate solubilization (44.76 ± 1.5 μg/ml). Enhanced germination index and germination rate of pea seeds under the LJH19 inoculation further supported the bacterium’s PGP potential. Whole-genome sequencing (3,602,821 bps) and genome mining endorsed the cold adaptation, degradation of polysaccharides, and PGP traits of LJH19. Biosynthetic gene clusters for type III polyketide synthase (PKS), terpene, and siderophore supplemented the endorsement of LJH19 as a potential PGP bacterium. Comparative genomics within the genus revealed 217 unique genes specific to hydrolytic and PGP activity. Conclusion The physiological and genomic evidence promotes LJH19 as a potentially safe bio-inoculant to formulate psychrotrophic bacterial consortia for accelerated degradation and improved night-soil compost.